Shape memory alloys, such as TiNi alloys, have been applied widely in medical fields (e.g. as a urethra arterial stent for enlarged prostate) due to their unique shape memory effect, high strength and excellent biocompatibility. However, these alloys show some obvious disadvantages, such as high manufacturing cost, limited recoverable deformation and lack of biodegradability.
Recently, biodegradable shape-memory polymers (SMPs) have attracted much attention and several kinds of biodegradable polymers have been reported. Specifically, SMPs can be produced from different natural or synthetic raw polymers, such as chitosan, cellulose, polyetherurethanes, poly(ε-caprolactone). The synthesis and post treatment methods of the polymers were complicated and the mechanical properties are insufficient for various biomedical applications.